As a physician involved in preventive medicine, I often ask my patients how they rate their current level of stress. Few ever say their stress levels are low. Most admit they're completely stressed out. In the process of exploring why, I've discovered a common denominator. These people feel overloaded. Most of us are trying to do too much. And it's a hard habit to break, because our age views multitasking as the normal way of getting things done. If we're not juggling a dozen different commitments at once, we tend to think there's something wrong with us.
From a medical perspective, however, the opposite is true.
Scientists are studying what happens to us when we try to do too much for too long, and the results are eye-opening.
There's no doubt that the human body is exquisitely adapted to deal with stress in brief doses. Our 'fight or flight' response is one example of the way that short bursts of heightened energy and vigilance can actually save our lives. But we aren't well adapted to deal with surges of adrenaline and cortisol -- two major stress hormones -- day after day. In evolutionary terms, traffic jams, two-career marriages, and kids involved in six after-school activities were not part of the plan.
Bruce McEwen, director of the neuroendocrinology lab at Rockefeller University, has studied the wear-and-tear effect of chronic stress on rats. As he describes in a book he co-authored, The End of Stress as We Know It (Joseph Henry Press, 2002), McEwen and his colleagues began restraining lab rats during their normal resting period. The resulting surge in stress hormones began to drop off earlier each day as the rats seemingly grew accustomed to the ordeal. But within three weeks the chronic stress began catching up with them. They grew anxious and aggressive. Their immune systems weakened. In their brains, the nerves in the hippocampus, a region involved in memory, began to shrink and stopped regenerating. The rats were burning out.
It appears that humans respond in much the same way. Chronically high cortisol levels lead to a number of health effects, including insulin resistance and poor sleep patterns. This reinforces bad eating habits, which then can trigger a fatigue that saps our desire to exercise. It's a vicious cycle. High cortisol levels can also lead to the production of cytokines, a protein that promotes inflammation. Cytokines have been linked to heart disease, depression, and inflammatory illnesses like arthritis and fibromyalgia.
Eventually, chronic stress can overtax the endocrine glands that make cortisol and other hormones, including the adrenal glands (atop the kidneys) and the thyroid (in the neck). Given that the endocrine system controls so many crucial processes in the body, depleted hormone levels can seriously disrupt our health.
I saw a man not too long ago who could only get five or six hours of sleep. We ruled out the obvious causes for insomnia, including sleep apnea, restless leg syndrome, depression, excess caffeine, and chronic pain. He was a doctor who often found himself lying awake at night thinking about his responsibilities. Along with his sleep problem, he had begun having bouts of atrial fibrillation, a disorder marked by an irregular heartbeat. He had begun to feel very 'old.'
Endocrine tests revealed low thyroid activity as well as extremely low levels of testosterone and cortisol. Thanks to a look into his brain via MRI, we noted that his pituitary gland, a key regulator of the endocrine system, had shrunk as well.
The treatment was two-pronged: We put him on hormone replacements, and he retired. In his words, 'the stress was just too much.' Within six months he reported feeling well, his dentist noted that his gums were 'rejuvenated,' his sex life improved, and so did his heart irregularity. Even more interesting, he started getting the restorative, undisrupted sleep he badly needed.
What started his troubles? We had no definite answer. His sleep problems may have been caused by his endocrine disorder, but there was another possibility. It could be that his overloaded life led to chronic stress, and the resulting cascade of ill effects included a withered endocrine system. If I had to hedge my bets, I'd go with the latter explanation.
Chronic stress has been shown to weaken our immune system, strain the heart, damage memory cells in the brain, and cause the insulin resistance that leads to type 2 diabetes. It has been implicated in cancer, depression, and even rheumatoid arthritis.
The bottom line is that we need to take responsibility for slowing down. To a stressed-out patient (or friend) I'd say: Try to limit your commitments. Give yourself time to rest, to exercise, and to eat sensibly. Stop at one drink, limit the caffeine, and definitely don't smoke cigarettes. Here's one more: Control your impulse to multitask! In the effort to do too much, we actually accomplish less. Rediscover the pleasure and surprising efficiency of doing one thing at a time. Most of us harbor a nagging belief that a slower life is a luxury we can't afford. Our bodies tell us otherwise. Slowing down is essential to our health.
Dan Beskind, M.D., M.P.H. is medical director of Southwest Preventive Health, an integrative health center located in Tucson, Arizona (www.southwestpreventivehealth.com). He also lectures on preventive health and hosts a radio show on KNST in Tucson called An Ounce of Prevention.